The present invention relates to a semiconductor device lo and more specifically to a high voltage generator and a method for regulating the high voltage.
Generally, IC chips (e.g., flash memory) have circuits that require a voltage larger than a power supply voltage.
A high voltage generator for supplying a voltage larger than the power supply voltage generates the voltage by using a charge pump driven in accordance with a clock signal generated by an oscillator. Here, the high voltage generator further includes a regulator so as to maintain a constant output voltage from the charge pump. In particular, the high voltage generator compares the output voltage of the charge pump and a reference voltage, generates the clock signal through the oscillator when the output voltage of the charge pump is smaller than the reference voltage, and drives the charge pump using the clock signal. However, the high voltage generator cuts off the generation of the clock signal when the output voltage of the charge pump is higher than the reference voltage.
In certain situations, the power to the semiconductor device may be cut off unexpectedly. This would cut off to the supply of the power supply voltage and may prevent a high voltage outputted from the charge pump not to be discharged to the ground, and instead be directed to an input terminal of a comparing circuit included in the regulator. The transistor in the comparing circuit may be damaged as a result.